The present disclosure relates to image forming apparatuses having a normal mode and a power save mode.
Recently, in response to increasing demands for power saving, various types of image forming apparatuses having a power save mode to reduce power consumption have been proposed.
Some type of image forming apparatus includes a master controller that controls the entire apparatus and a slave controller that controls a printing section (mechanism that executes a print job) upon receipt of an instruction from the master controller.
In order for the image forming apparatus with this configuration to return from the power save mode to the normal mode, a return request is output from the master controller to the salve controller, for example. As one example, when the image forming apparatus receives a print request from a user terminal, the master controller outputs the return request to the slave controller. Also, when the state of the apparatus (e.g., a paper accommodation state) changes, the master controller outputs the return request to the slave controller. It is noted that some type of image forming apparatus suspends communication functions (functions to communicate information on a print job, information on an apparatus state, etc.) of the master controller and the slave controller in the power save mode. Accordingly, in such an image forming apparatus, the master controller and the slave controller are connected together through, for example, a signal line (hereinafter referred to as a first signal line for the convenience sake) to output the return request from the master controller to the slave controller.
For example, when the master controller outputs to the slave controller a return request in response to a print request received from a user terminal, the slave controller allows the printing section to perform a warm-up operation necessary for execution of the print job in a return. Further, when the master controller outputs to the slave controller a return request in response to change in apparatus state (where operation of the printing section is unnecessary), the slave controller notifies the master controller of information indicating the apparatus state in the return. However, in order to save on wasteful power consumption, the slave controller allows the printing section not to perform the warm-up operation.
As described above, various processing must be performed in a return from the power save mode to the normal mode (e.g., processing to allow the printing section to perform the warm-up operation, processing to allow the printing section not to perform the warm-up operation, etc.). However, the slave controller cannot recognize processing to be performed in a return only with the return request from the master controller. For this reason, after outputting the return request to the slave controller, the master controller is required to wait until the communication functions suspended in the power save mode become operable and then provide to the slave controller an instruction on processing to be performed in a return. However, in this case, only after the communication functions suspended in the power save mode become operable, the processing to be performed in the return from the power save mode to the normal mode is determined. As a result, the processing to be performed in the return starts with delay.
In order to solve the aforementioned problem, in some cases, a signal line (hereinafter referred to as a second signal line for the convenience sake) may be provided besides the first signal line for output of the return request from the master controller to the slave controller. The master controller outputs an instruction on processing to be performed in a return to the slave controller through the second signal line. With this configuration, the master controller can output to the slave controller an instruction on processing to be performed in a return without the need to wait until the communication functions suspended in the power save mode become operable.